2 * c 2001 PPC 64 Team, IBM Corp
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
10 #include <linux/slab.h>
11 #include <linux/vmalloc.h>
13 #include <asm/uaccess.h>
14 #include <asm/pgalloc.h>
15 #include <asm/pgtable.h>
16 #include <asm/semaphore.h>
18 static DECLARE_MUTEX(imlist_sem);
19 struct vm_struct * imlist = NULL;
21 static int get_free_im_addr(unsigned long size, unsigned long *im_addr)
24 struct vm_struct **p, *tmp;
27 for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
28 if (size + addr < (unsigned long) tmp->addr)
30 if ((unsigned long)tmp->addr >= IMALLOC_START)
31 addr = tmp->size + (unsigned long) tmp->addr;
32 if (addr > IMALLOC_END-size)
40 /* Return whether the region described by v_addr and size is a subset
41 * of the region described by parent
43 static inline int im_region_is_subset(unsigned long v_addr, unsigned long size,
44 struct vm_struct *parent)
46 return (int) (v_addr >= (unsigned long) parent->addr &&
47 v_addr < (unsigned long) parent->addr + parent->size &&
51 /* Return whether the region described by v_addr and size is a superset
52 * of the region described by child
54 static int im_region_is_superset(unsigned long v_addr, unsigned long size,
55 struct vm_struct *child)
57 struct vm_struct parent;
59 parent.addr = (void *) v_addr;
62 return im_region_is_subset((unsigned long) child->addr, child->size,
66 /* Return whether the region described by v_addr and size overlaps
67 * the region described by vm. Overlapping regions meet the
68 * following conditions:
69 * 1) The regions share some part of the address space
70 * 2) The regions aren't identical
71 * 3) Neither region is a subset of the other
73 static int im_region_overlaps(unsigned long v_addr, unsigned long size,
76 if (im_region_is_superset(v_addr, size, vm))
79 return (v_addr + size > (unsigned long) vm->addr + vm->size &&
80 v_addr < (unsigned long) vm->addr + vm->size) ||
81 (v_addr < (unsigned long) vm->addr &&
82 v_addr + size > (unsigned long) vm->addr);
85 /* Determine imalloc status of region described by v_addr and size.
86 * Can return one of the following:
87 * IM_REGION_UNUSED - Entire region is unallocated in imalloc space.
88 * IM_REGION_SUBSET - Region is a subset of a region that is already
89 * allocated in imalloc space.
90 * vm will be assigned to a ptr to the parent region.
91 * IM_REGION_EXISTS - Exact region already allocated in imalloc space.
92 * vm will be assigned to a ptr to the existing imlist
94 * IM_REGION_OVERLAPS - Region overlaps an allocated region in imalloc space.
95 * IM_REGION_SUPERSET - Region is a superset of a region that is already
96 * allocated in imalloc space.
98 static int im_region_status(unsigned long v_addr, unsigned long size,
99 struct vm_struct **vm)
101 struct vm_struct *tmp;
103 for (tmp = imlist; tmp; tmp = tmp->next)
104 if (v_addr < (unsigned long) tmp->addr + tmp->size)
108 if (im_region_overlaps(v_addr, size, tmp))
109 return IM_REGION_OVERLAP;
112 if (im_region_is_subset(v_addr, size, tmp)) {
113 /* Return with tmp pointing to superset */
114 return IM_REGION_SUBSET;
116 if (im_region_is_superset(v_addr, size, tmp)) {
117 /* Return with tmp pointing to first subset */
118 return IM_REGION_SUPERSET;
120 else if (v_addr == (unsigned long) tmp->addr &&
122 /* Return with tmp pointing to exact region */
123 return IM_REGION_EXISTS;
128 return IM_REGION_UNUSED;
131 static struct vm_struct * split_im_region(unsigned long v_addr,
132 unsigned long size, struct vm_struct *parent)
134 struct vm_struct *vm1 = NULL;
135 struct vm_struct *vm2 = NULL;
136 struct vm_struct *new_vm = NULL;
138 vm1 = (struct vm_struct *) kmalloc(sizeof(*vm1), GFP_KERNEL);
140 printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
144 if (v_addr == (unsigned long) parent->addr) {
145 /* Use existing parent vm_struct to represent child, allocate
146 * new one for the remainder of parent range
148 vm1->size = parent->size - size;
149 vm1->addr = (void *) (v_addr + size);
150 vm1->next = parent->next;
155 } else if (v_addr + size == (unsigned long) parent->addr +
157 /* Allocate new vm_struct to represent child, use existing
158 * parent one for remainder of parent range
161 vm1->addr = (void *) v_addr;
162 vm1->next = parent->next;
165 parent->size -= size;
168 /* Allocate two new vm_structs for the new child and
169 * uppermost remainder, and use existing parent one for the
170 * lower remainder of parent range
172 vm2 = (struct vm_struct *) kmalloc(sizeof(*vm2), GFP_KERNEL);
174 printk(KERN_ERR "%s() out of memory\n", __FUNCTION__);
180 vm1->addr = (void *) v_addr;
184 vm2->size = ((unsigned long) parent->addr + parent->size) -
186 vm2->addr = (void *) v_addr + size;
187 vm2->next = parent->next;
189 parent->size = v_addr - (unsigned long) parent->addr;
196 static struct vm_struct * __add_new_im_area(unsigned long req_addr,
199 struct vm_struct **p, *tmp, *area;
201 for (p = &imlist; (tmp = *p) ; p = &tmp->next) {
202 if (req_addr + size <= (unsigned long)tmp->addr)
206 area = (struct vm_struct *) kmalloc(sizeof(*area), GFP_KERNEL);
210 area->addr = (void *)req_addr;
218 static struct vm_struct * __im_get_area(unsigned long req_addr,
222 struct vm_struct *tmp;
225 status = im_region_status(req_addr, size, &tmp);
226 if ((criteria & status) == 0) {
231 case IM_REGION_UNUSED:
232 tmp = __add_new_im_area(req_addr, size);
234 case IM_REGION_SUBSET:
235 tmp = split_im_region(req_addr, size, tmp);
237 case IM_REGION_EXISTS:
238 /* Return requested region */
240 case IM_REGION_SUPERSET:
241 /* Return first existing subset of requested region */
244 printk(KERN_ERR "%s() unexpected imalloc region status\n",
252 struct vm_struct * im_get_free_area(unsigned long size)
254 struct vm_struct *area;
258 if (get_free_im_addr(size, &addr)) {
259 printk(KERN_ERR "%s() cannot obtain addr for size 0x%lx\n",
265 area = __im_get_area(addr, size, IM_REGION_UNUSED);
268 "%s() cannot obtain area for addr 0x%lx size 0x%lx\n",
269 __FUNCTION__, addr, size);
276 struct vm_struct * im_get_area(unsigned long v_addr, unsigned long size,
279 struct vm_struct *area;
282 area = __im_get_area(v_addr, size, criteria);
287 unsigned long im_free(void * addr)
289 struct vm_struct **p, *tmp;
290 unsigned long ret_size = 0;
294 if ((PAGE_SIZE-1) & (unsigned long) addr) {
295 printk(KERN_ERR "Trying to %s bad address (%p)\n", __FUNCTION__, addr);
299 for (p = &imlist ; (tmp = *p) ; p = &tmp->next) {
300 if (tmp->addr == addr) {
301 ret_size = tmp->size;
309 printk(KERN_ERR "Trying to %s nonexistent area (%p)\n", __FUNCTION__,